Exemption from informed consent: When it is possible in investigational product and drug trials?

One of the most important ethical step in conducting investigational product trials or drug trials is obtaining informed consent from the participants. Although consent from the participants regarding participation is of prime importance but is not always practical or feasible. There may be several instances where it is practically impossible to obtain informed consent, whereas in some cases, obtaining informed consent from the trial participants adversely affects the quality and validity of the study data. Obtaining informed consent is a highly complex and technical process if the participants are not literate or suffering from a terminal illness, Also in some instances obtaining informed consent regarding the washout of prior prescribed medicine which may affect the trial outcomes. Although many guidelines exist for obtaining proper informed consent while very scarce literature exists on the instances where it can be waived off. Therefore, this brief narrative review aims to provide insight into currently available knowledge about when to obtain informed consent during testing of investigational product trials and drug trials and other possible scenarios where it can be waived off considering the effects of the washout period.